Howdy All,

Now that everybody's had their morning coffee...

When Installing an EGT thermocouple in the exhaust manifold,I thought I read you should drill into the rear,or left side(looking from over the passenger fender)section of the divided manifold outlet...correct?

Ok,here's the thinky-part...I thought I read that the hottest,or leanest running cyl is #1?

Wouldn't it make sense to monitor the side of the manifold that contains exhaust from the cyl that gets the hottest? Soooo,wouldn't that be the front or right side?

Ok,straighten me out on this one...

Oh yeah,by the way...any detailed instructions on EGT installation that you want to send my way will be carefully read and applied to my upcoming ordeal...

As usual,thanks in advance for all the help,you'se guy's...

Vinny

 

Well, there is some debate over the "hottest" gasses, but the facts seem to be that #1 runs rich, and therefore a little hotter than the rest, but #6 gets less cooling from the water jacket, so actually tends to seize first.

I drilled the front runner of my manifold. I had the turbo off to swap housings, so I picked the thickest spot and tried to center the tip of the thermocouple in the gas flow, and make sure that the pipe to tubing adapter was flush with the runner.

It is pretty easy, if you know how to use a drill and a tap .

You won't have any trouble --

 

OK, I got another question along the same lines here. I'll be putting a pyro on my truck too. I want to remove the turbo to make absolutely sure I get all the metal chips out. How much of a PITA is it to remove the turbo? By that I mean how big of an oil stain will I have on my dirveway? And what are the torque specs for the reinstall? I know it isn't competely necessary to remove the turbo, and lots of people have drilled with it on and had no problems... but I'm willing to take the extra time to make sure its right. I plan to keep this truck for many more years. Thanks in advance for the help!!!
-Dave

 

I just did my 93, you only need to unbolt the 4 -15mm bolts at the mani/turbo joint, and unbolt the exhaust pipe mount on tne trans and pull it out the way. Its a little tight but can get it far enough back to replace the gasket and put a piece of cardboard inbetween while drilling and tapping, after doing mine I will never do it using a vacume and greasing the drill/tap. Its too much of a gamble IMO. When its apart you will see the best place to drill, I have seen different measurements for this, some say 2" in and 5/8 off center, this is close ,but not good for me. I put it in the rear section as most do it seems and so far it has worked great.

 

If you havent already look at
http://www.tstproducts.com/gauge_install.html

 

Pulling the whole turbo is no big deal. I've pulled mine twice, the part that takes the longest is scraping the rock-hard oil return gasket off the turbo and the return pipe. I drilled my manifold when I swapped on my WH1C, I just did it by eyeball based on where I'd seen other guys put it. There's a pic in my gallery that shows the WH1C and the pipe plug in my manifold. Torque spec? I just tightened it up in a cross pattern both times with a box-end wrench, no leaks. With how easy pulling the turbo is, I wouldn't drill with it in place.

 

Your REALLY don't need to pull the turbo... honest....

You can do the all the work with the turbo on the truck. I've seen so many done this way I've lost count... including my own truck and my brothers truck as well.
FYI... if a cylinder is running lean it will be running cooler than the rest. On a gas engine it would be much hotter, but not on a diesel engine. It's just the opposite...
To do the pyro job just center punch your chosen drill location, use heavy axle grease on the tip of the drill and go to it. After a bit, stop and clean off the drill tip, regrease it and carry on... do this 2 or 3 times until you break thru.
Then at that point use a pencil magnet to "fish" for any shaving that MIGHT have made it into the manifold.
When you done "fishing" do the same process with the tap... grease and tap, remove, grease and tap....
After a bit remove the tap, and thread in the theromcouple fitting to check for depth.... remember it's an NPT thread which is tapered so you don't wanna go to far.
Once your done tapping, go "fishing" again.
Install the thermocouple, snug it all down and connect your wiring.
When your ready, start the truck and let it idle for a few seconds/minute or two.
That will "puff" any shavings that might have remained inside. They will not damage anything so don't worry..

Hope that helps...

pastor Bob.

 

Bob is right, I too have done a lot of these and it is easy.


Dave

 

Im just over cautious I guess. It seemed risky, when you drill it looks like any chips will fall right into the turbo because of the downward slope of the casting. Ah well, its easy to move the turbo as well. At least on the first gens.

 

did the grease/magnet method on mine as well, no damage done
we put the magnet on the manifold while drilling as well, the attract any stragglers

 

I think I would have spent more time messing with grease and magnets than I spent pulling the turbo. I'm not saying that it can't/shouldn't be done with the turbo on, I just think that with as easy as it is to pull the turbo, why mess with grease and magnets?

 

I know what you mean...

Done with grease and magnets...sounds like a magic trick!

With my luck,my turbo would eat a big shaving in EXACTLY the wrong spot(wherever the heck that is)...

Heck,it's only four bolts...you can count on the fact that I'll be takin'mine off when I do it.

Vinny

 

Alec you have it right backwards on the cylinders. Number one gets the most air because it is closer to the feed. They all get the same fuel because of injection. So number one is leaner than the number 6 which gets the same fuel but less air.

Any problems in the cooling system, it boils and creates an air pocket which goes to number one cylinder. Got that one down pat, lost the engine twice over that issue. Trashed the number one cylinder twice in a thousand miles.

So number six burns hotter because of less air, the thermocouple should go in the rear runner as it is the hottest.

If you have a cooling problem and too hot an engine temperature, number one will go first. If you are running at max with the EGT's, number six will go first because of less air and hotter EGT's.

 

Not really..unless you have to go looking for grease. I just did my son's truck...you grease and clean the drill a couple of times, fish for chips once afte drilling, once after tapping...added time for that is maybe one minute.
Plus when the truck is turned over anything left will just "ease" out thru the turbo.
You can pull the turbo if it makes you feel better....but it really is not necessary.
I think there's more potential danger when changing out fuel injectors...especially if they've been in there for 10 or more years....but that's another topic entirely.
Good luck no matter which method you choose...the addition of a pyrometer is worth the trouble.
Jay

 

I have never burned up one of these engines, so maybe I have the wrong dope, but looking at the shape of the #1 air path -- it is almost "j" shaped -- supports what I have read, which is that #1 gets less air than the other cylinders.

From the FAQ at http://dodgeram.org/tech/dsl/FAQ/turbo_faq.htm
As for cooling, Hdm48 posted that he has seen a number of engines score the #6 cylinders under high HP operation due to inadequate cooling . . . the water has to flow back there past the first five cylinders.

Gasses should not get trapped around the #1 cylinder -- but this is not a condition that I am familiar with, so I can't say anything about it.

What were you doing when you toasted your engine?